I've handed mine to several friends who, after moving it around just a couple of passes back and forth, exclaimed that the right/left reversal was impossible for them to deal with. These have all been either non-photographers or those who have shot only 35mm and digital, though. It's not the best for fast moving subjects, true, but otherwise I got used to it in pretty short order.

They sound like the same friends I have. I let them look under the dark cloth of one of my large format cameras and they can't understand how I can take a picture of something upside down on the ground glass.

Like you said, you just mess with it awhile and you get used to it. I don't even think about it any more with my Blad with waist level finder.

Now if I can just get the autofocus to work the way I want on my Nikon D300.